I'm doing it for the first time this year as well. I hear it's fast and flowy. I usually run a 32/20 on my 29er but am toying with the idea of a 19t or even an 18t depending on how much training I can get done this winter. 25 miles is a long way to be pushing too hard of a gear. Then again, I don't want to be spinning like mad for 4 hours either!

In 2009 I ran a 33x18 (53" gear) and was having a hard time hanging on the flat fireroad sections. Last year was wet and I ran a 32x17 (54.5" gear) and that was pretty good. There is only one real climb, Major Mike, and its not really that big a deal.
Here's my report from last year.

I raced in 2009 and 2010 as well. My normal SS gearing (29er) is 34x24 to get me up the long steep hills around here. Both years I switched my cog to a 22t, so 34x22. I have no idea what that is in gear inches, sorry!

In 2009, the race was about 20 miles and dry, and was spinning alot on the fireroads, but on the singletrack it worked well, and the race is mostly singletrack after all! I think a 21t cog would have been ideal for me that year.

In 2010, as CB@ said, it was wet and got really muddy, the race was longer (25 miles I think), and it was a month earlier, so lett training time. I think my gear was perfect *for me* last year.

This year, I will make my gearing decision a day or 2 before race day. It will depend on how much riding I've gotten in and the weather, but it will be somewhere around 34x22 to 34x20.

Then again, I heard the winner was running over a 2x1 ratio!

As you've probably heard, the course ir relatively flat, with one moderate climb and a bunch or short steep hills. Lots of twisty flowy singletrack with sections of dirt or paved roads to connect everything. It's a great place for a SS race, I'm definately looking forward to it again!

I have run 34:20, 32:18, and 33:17 on a 29er in different races at Stewart. For SSAP course, I will probably run 32:18, which is what I ran last year when I finished 10th in sport. The way this winter is going, it may be quite wet in mid-April.

The terrain is rolling with no major climbs- a few short, steep grunts, step-up moves over rocks ledges, etc. but no sustained climbing. Most of the climbs you can blast up at full speed.

I ran 33:17 for last years DH40- it was fast but I began suffering greatly mid-way into the second lap. Originally on pace for a 3:30ish finish, I eventually crossed the line in a lackluster 3:48.